motherboard problem

One of my computers is an emachine T1860, with 18000+ AMD Athlon XP Processor. After a while it started freezing when it was running a program, and i had to manually shut it off everytime. At one point the computer just stopped turning on. There is no bios warning beeps, the fans turn on, but the monitor stays in standby mode and the red light on the motherboard turns on for a second then turns off. Also the main power light and the CD ROM light does not turn on. I have tried switching the graphics card and ram with no sucess. I have come to a conclusion that my motherboard is dead but before i go out and buy a new one, i want to make sure.